CN110985222B

CN110985222B - Method and system for triggering DPF passive regeneration

Info

Publication number: CN110985222B
Application number: CN201911267892.0A
Authority: CN
Inventors: 何乃鹏; 马广营; 王坤
Original assignee: Weichai Power Co Ltd
Current assignee: Weichai Power Co Ltd
Priority date: 2019-12-11
Filing date: 2019-12-11
Publication date: 2022-08-05
Anticipated expiration: 2039-12-11
Also published as: CN110985222A

Abstract

The invention provides a method and a system for triggering DPF passive regeneration, wherein the method comprises the following steps: when the engine runs, recording the running time of the engine and periodically detecting the first temperature of the DPF; calculating the average temperature of the DPF during the operating time period when the operating time period is equal to the time threshold value; if the average temperature is lower than the condition temperature, starting a heat management mode of the engine, and raising the exhaust temperature of the engine to a second temperature; and if the average value of the average temperature and the second temperature is greater than or equal to the condition temperature, determining to trigger the DPF passive regeneration, and stopping the thermal management mode. In the present aspect, when the engine operating duration is equal to the time threshold, the average temperature within the operating duration is calculated. And if the average temperature is lower than the condition temperature, the exhaust temperature of the engine is raised to a second temperature, and the DPF passive regeneration is triggered. The problem that the DPF cannot be triggered to be passively regenerated due to the use of the working condition is avoided, the oil consumption of the vehicle is reduced, and the power of the vehicle is ensured.

Description

Method and system for triggering DPF passive regeneration

Technical Field

The invention relates to the technical field of diesel engines, in particular to a method and a system for triggering DPF passive regeneration.

Background

With the development of science and technology, environmental protection becomes one of the most concerned focuses of all industries. Especially for the automobile industry, the exhaust gas of the engine needs to be treated to reach the emission standard.

At present, Diesel engines of the national six standards are all provided with particle traps (DPF), and the DPF is used for treating gas discharged by the Diesel engines to enable the gas to meet the emission standard. In the DPF, too much soot usually occurs, and the soot removal method is a passive regeneration function and an active regeneration function of the DPF. However, due to the use conditions of vehicles such as road rollers, excavators and bulldozers, the load of the diesel engine is low, and the temperature of the diesel engine cannot trigger the passive regeneration function of the DPF, so that the active regeneration function of the DPF can be frequently triggered, and the oil consumption and the power of the vehicle are seriously affected.

Disclosure of Invention

In view of this, embodiments of the present invention provide a method and a system for triggering a DPF passive regeneration, so as to solve the problem that the fuel consumption and power of a vehicle are affected because the DPF passive regeneration function cannot be triggered due to the use condition at present.

In order to achieve the above purpose, the embodiments of the present invention provide the following technical solutions:

the embodiment of the invention discloses a method for triggering DPF passive regeneration in a first aspect, which comprises the following steps:

recording the running time of the engine and periodically detecting the first temperature of a particulate trap (DPF) when the engine runs;

calculating an average temperature of the DPF during the operating period using the first temperature when the operating period is equal to a time threshold;

if the average temperature is lower than the preset condition temperature, starting a heat management mode of the engine, and raising the exhaust temperature of the engine to a second temperature;

and if the average value of the average temperature and the second temperature is greater than or equal to the conditional temperature, determining to trigger DPF passive regeneration, and stopping the heat management mode of the engine.

Preferably, the periodically detecting a first temperature of the particulate trap DPF comprises:

periodically detecting the air inlet temperature and the exhaust temperature of the DPF;

determining an intake air temperature of the DPF as a first temperature of the DPF;

alternatively, determining the exhaust temperature of the DPF to be the first temperature;

alternatively, the average of the intake air temperature and the exhaust gas temperature of the DPF is determined as the first temperature.

Preferably, the starting the thermal management mode of the engine to raise the exhaust temperature of the engine to a second temperature includes:

activating a device in a preset device set of the engine to raise the exhaust temperature of the engine to a second temperature.

Preferably, after the stopping of the thermal management mode of the engine, the method further includes:

and clearing the operation time length.

Preferably, after calculating the average temperature of the DPF within the time threshold using the first temperature, the method further includes:

and if the average temperature is greater than or equal to the condition temperature, determining to trigger DPF passive regeneration, and resetting the operation time length.

In a second aspect of the embodiments of the present invention, a system for triggering a passive regeneration of a DPF is disclosed, the system comprising:

the processing unit is used for recording the running time of the engine and periodically detecting the first temperature of the DPF when the engine runs;

a calculation unit for calculating an average temperature of the DPF within the operation period using the first temperature when the operation period is equal to a time threshold;

the starting unit is used for starting a heat management mode of the engine and raising the exhaust temperature of the engine to a second temperature if the average temperature is lower than a preset condition temperature;

and the stopping unit is used for determining to trigger DPF passive regeneration and stopping the heat management mode of the engine if the average value of the average temperature and the second temperature is greater than or equal to the conditional temperature.

Preferably, the processing unit includes:

the detection module is used for periodically detecting the air inlet temperature and the exhaust temperature of the DPF;

a determining module for determining an intake temperature of the DPF as a first temperature of the DPF, or determining an exhaust temperature of the DPF as the first temperature, or determining an average of the intake temperature and the exhaust temperature of the DPF as the first temperature.

Preferably, the starting unit is specifically configured to: activating a device in a preset device set of the engine to raise the exhaust temperature of the engine to a second temperature.

Preferably, the stopping unit is further configured to: and clearing the operation time length.

Preferably, the system further comprises:

and the clearing unit is used for determining to trigger DPF passive regeneration and clearing the running time length if the average temperature is greater than or equal to the condition temperature.

Based on the method and the system for triggering the passive regeneration of the DPF provided by the embodiment of the invention, the method comprises the following steps: when the engine runs, recording the running time of the engine and periodically detecting the first temperature of the DPF; calculating the average temperature of the DPF during the running time period by using the first temperature when the running time period is equal to the time threshold value; if the average temperature is lower than the preset condition temperature, starting a heat management mode of the engine, and raising the exhaust temperature of the engine to a second temperature; and if the average value of the average temperature and the second temperature is greater than or equal to the condition temperature, determining to trigger the DPF to perform passive regeneration, and stopping the heat management mode of the engine. In the present aspect, when the engine operating duration is equal to the time threshold, the average temperature within the operating duration is calculated. And if the average temperature is lower than the condition temperature, starting a thermal management mode to raise the exhaust temperature of the engine to a second temperature until the average value of the average temperature and the second temperature is higher than or equal to the condition temperature, determining to trigger the DPF to passively regenerate, and stopping the thermal management mode. The problem that the DPF cannot be triggered to regenerate passively due to the use condition of the engine is avoided, so that frequent triggering of DPF active regeneration is avoided, the oil consumption of a vehicle is reduced, and the power of the vehicle is guaranteed.

Drawings

In order to more clearly illustrate the embodiments of the present invention or the technical solutions in the prior art, the drawings used in the description of the embodiments or the prior art will be briefly described below, it is obvious that the drawings in the following description are only embodiments of the present invention, and for those skilled in the art, other drawings can be obtained according to the provided drawings without creative efforts.

FIG. 1 is a flow chart of a method of triggering passive regeneration of a DPF in accordance with an embodiment of the present invention;

FIG. 2 is a schematic diagram of a temperature profile provided by an embodiment of the present invention;

FIG. 3 is a schematic diagram of control logic for triggering DPF passive regeneration according to an embodiment of the present invention;

fig. 4 is a block diagram of a system for triggering passive regeneration of a DPF according to an embodiment of the present invention.

Detailed Description

The technical solutions in the embodiments of the present invention will be clearly and completely described below with reference to the drawings in the embodiments of the present invention, and it is obvious that the described embodiments are only a part of the embodiments of the present invention, and not all of the embodiments. All other embodiments, which can be derived by a person skilled in the art from the embodiments given herein without making any creative effort, shall fall within the protection scope of the present invention.

In this application, the terms "comprises," "comprising," or any other variation thereof, are intended to cover a non-exclusive inclusion, such that a process, method, article, or apparatus that comprises a list of elements does not include only those elements but may include other elements not expressly listed or inherent to such process, method, article, or apparatus. Without further limitation, an element defined by the phrase "comprising an … …" does not exclude the presence of other identical elements in a process, method, article, or apparatus that comprises the element.

As can be known from the background art, in the use process of vehicles such as road rollers, excavators and bulldozers at present, the load of a diesel engine is low due to the use working conditions, and the temperature of the diesel engine cannot trigger the passive regeneration function of the DPF, so that the active regeneration function of the DPF can be frequently triggered, and the oil consumption and the power of the vehicles are seriously influenced.

Accordingly, embodiments of the present invention provide a method and system for triggering passive regeneration of a DPF by calculating an average temperature over an operating time period when the engine operating time period is equal to a time threshold. And if the average temperature is lower than the condition temperature, the exhaust temperature of the engine is raised to a second temperature, and the DPF passive regeneration is triggered. The problem that the DPF cannot be triggered to be passively regenerated due to the use of working conditions is avoided, so that the oil consumption of the vehicle is reduced, and the power of the vehicle is ensured.

The DPF active regeneration request means: the engine actively injects Hydrocarbon (HC), and the HC is oxidized inside an Oxidation Catalyst (DOC) to make the active regeneration temperature of the DPF reach a certain temperature (for example, 600 ℃), and carbon dioxide is generated by the reaction of oxygen and carbon, thereby eliminating the carbon deposition in the DPF.

DPF passive regeneration refers to: the nitrogen dioxide emitted by the engine chemically reacts with soot in the DPF, i.e., the nitrogen dioxide reacts with the carbon to produce carbon dioxide and nitrogen monoxide, thereby eliminating the soot in the DPF, and the triggering of the passive regeneration of the DPF is temperature dependent.

Carbon loading: soot weight inside the DPF.

Referring to fig. 1, a flow chart of a method for triggering a passive regeneration of a DPF according to an embodiment of the present invention is shown, the method comprising the steps of:

step S101: while the engine is running, the running time of the engine is recorded and the first temperature of the DPF is periodically detected.

In the process of implementing step S101, when the engine is running, an Electronic Control Unit (ECU) is used to record the running time of the engine. The intake temperature and the exhaust temperature of the DPF are periodically detected, and the first temperature is determined by combining the intake temperature and the exhaust temperature of the DPF.

In determining the first temperature of the DPF, an intake air temperature of the DPF is determined to be the first temperature, or an exhaust temperature of the DPF is determined to be the first temperature, or an average of the intake air temperature and the exhaust temperature of the DPF is determined to be the first temperature. In the embodiment of the present invention, a specific determination manner of the first temperature is not particularly limited.

Step S102: when the operating duration is equal to the time threshold, an average temperature of the DPF during the operating duration is calculated using the first temperature.

In the process of implementing step S102 specifically, a time threshold is preset, and when the operating duration is equal to the time threshold, the average temperature of the DPF during the operating duration is calculated by using the plurality of sets of the first temperatures acquired and using a preset calculation method. For example: when the operation time is equal to 10 hours, the average temperature of the DPF within 10 hours is calculated by integration by using the collected multiple groups of first temperatures.

It should be noted that the setting of the time threshold may be set according to actual situations.

Step S103: and judging whether the average temperature is less than the condition temperature. If the average temperature is greater than or equal to the condition temperature, step S104 is executed, and if the average temperature is less than the condition temperature, step S105 is executed.

In the process of implementing step S103, a condition temperature is preset, and it is determined whether the average temperature is lower than the condition temperature, and if the average temperature is higher than or equal to the condition temperature, it indicates that the current temperature of the DPF may trigger the DPF passive regeneration. If the average temperature is less than the condition temperature, it indicates that the current temperature of the DPF cannot trigger the DPF passive regeneration.

For example: when the average temperature is more than or equal to 280 ℃, the current temperature of the DPF can trigger the DPF to perform passive regeneration. If the average temperature is less than 280 ℃, it indicates that the current temperature of the DPF cannot trigger the DPF passive regeneration.

It should be noted that the condition temperature may be set according to actual conditions.

Step S104: and determining to trigger DPF passive regeneration, and resetting the running time length.

In the process of specifically implementing the step S104, if the average temperature is greater than or equal to the condition temperature, it is indicated that the current temperature of the DPF can trigger the DPF passive regeneration, the operation time length is cleared, and a period for determining whether to trigger the DPF passive regeneration next time is entered.

That is, the length of time the engine is running is re-recorded and the first temperature of the DPF is re-sensed periodically.

Step S105: and starting a thermal management mode of the engine, and raising the exhaust temperature of the engine to a second temperature.

In the process of implementing step S105, devices in the preset device set of the engine are activated, and the exhaust temperature of the engine is raised to the second temperature. For example: and starting devices such as an air inlet throttle valve and an inter-cooling bypass, and raising the exhaust temperature of the engine to a second temperature.

Step S106: and if the average value of the average temperature and the second temperature is greater than or equal to the condition temperature, determining to trigger the DPF to perform passive regeneration, and stopping the heat management mode of the engine.

In the process of implementing step S106 specifically, it should be noted that the DPF passive regeneration may not necessarily be triggered after the exhaust temperature of the engine is raised to the second temperature, and in order to ensure that the DPF passive regeneration is triggered, the second temperature of the engine needs to be raised to a condition temperature or higher, where an average value of the average temperature and the second temperature is greater than or equal to the condition temperature.

That is, if the average value of the average temperature and the second temperature is greater than or equal to the condition temperature, determining to trigger the DPF passive regeneration, stopping the heat management mode of the engine, and clearing the operation time length.

And if the average value of the average temperature and the second temperature is less than the condition temperature, continuously increasing the exhaust temperature of the engine until the average value of the average temperature and the second temperature is more than or equal to the condition temperature, determining to trigger the DPF passive regeneration, stopping the heat management mode of the engine, and resetting the running time.

In an embodiment of the present invention, when the engine operating period is equal to the time threshold, the average temperature over the operating period is calculated. And if the average temperature is lower than the condition temperature, starting the thermal management mode to raise the exhaust temperature of the engine to a second temperature until the average value of the average temperature and the second temperature is greater than or equal to the condition temperature, ensuring that the DPF passive regeneration is triggered, and stopping the thermal management mode. The problem that the DPF cannot be triggered to regenerate passively due to the use condition of the engine is avoided, so that frequent triggering of DPF active regeneration is avoided, the oil consumption of a vehicle is reduced, and the power of the vehicle is guaranteed.

To better illustrate the thermal management mode referred to above for determining whether to start the engine based on the average temperature and the conditioned temperature, the timing for starting the thermal management mode of the engine is illustrated by the temperature profile shown in fig. 2, and by the profile corresponding to the first temperature in fig. 2 and the conditioned temperature. It should be noted that the content shown in fig. 2 is only for illustration.

In FIG. 2, the horizontal axis is time (in h), the vertical axis is temperature (in degrees Celsius), the conditioned temperature is set to 280 degrees Celsius, and the time threshold is set to 10 hours.

According to the curve corresponding to the first temperature shown in fig. 2, in the interval of 0 hour to 10 hours on the horizontal axis, the average temperature calculated from the first temperature is less than the condition temperature (280 degrees celsius), and the thermal management mode of the engine is started. The first temperature is controlled to be around 320 degrees celsius for a 10-20 hour interval on the horizontal axis, and the thermal management mode of the engine is stopped at 20 hours on the horizontal axis.

The average temperature calculated from the first temperature is greater than the conditioned temperature (280 degrees celsius) over the 20 to 30 hour interval on the horizontal axis, eliminating the need for a thermal management mode to start the engine.

To better explain the contents shown in fig. 1 of the above embodiment of the present invention, the description is made with reference to fig. 2.

While the engine is running, the running time of the engine and the first temperature of the DPF are recorded, and when the running time is equal to 10 hours, the average temperature of the DPF over 10 hours is calculated. If the average temperature (between 0 and 10 hours) is less than 280 degrees celsius, the engine's thermal management mode is initiated, e.g., the intake throttle and the mid-cool bypass are enabled, raising the engine's exhaust temperature to a second temperature. And stopping the heat management mode of the engine when the average value of the second temperature and the average temperature is greater than or equal to 280 ℃. And clearing the recorded operation time length, and entering the next judgment period (for example, 20-30 hour interval).

To better explain the contents of the steps in fig. 1 of the above embodiment of the present invention, the control logic for triggering the passive regeneration of the DPF is illustrated in fig. 3, and it should be noted that fig. 3 is only used for illustration.

Fig. 3 includes: the temperature control module comprises a temperature processing module 301, a switching module 302, a timing module 303, a first comparing module 304, a second comparing module 305, a third comparing module 306, a fourth comparing module 307, a first judging module 308 and a second judging module 309.

In fig. 3, the temperature processing module 301 calculates an average temperature of the DPF using the collected first temperature of the DPF. The temperature processing module 301 sends the average temperature to the second comparison module 305 and the third comparison module 306, respectively. The timing module 303 records the operating duration of the engine and sends the operating duration to the first and

fourth comparison modules

304, 307.

The first comparing module 304 determines whether the operation time is longer than or equal to 10 hours, and sends the determination result to the first determining module 308. The second comparing module 305 determines whether the average temperature is less than the condition temperature, and sends the determination result to the first determining module 308. The first determination module 308 determines that the operating time is greater than or equal to 10 hours and the average temperature is less than the conditioning temperature, and the first determination module 308 controls the switching module 302 to activate the thermal management mode of the engine. And determining to trigger the DPF passive regeneration until the average value of the average temperature and the second temperature is greater than or equal to the conditional temperature, stopping the heat management mode of the engine, and resetting the running time length by the timing module 303.

The third comparing module 306 determines whether the operation time is longer than or equal to 10 hours, and sends the determination result to the second determining module 309. The fourth comparing module 307 determines whether the average temperature is equal to or greater than the condition temperature, and sends the determination result to the second determining module 309. The second determination module 309 determines that the operating duration is greater than or equal to 10 hours and the average temperature is greater than or equal to the conditional temperature, the thermal management mode of the engine is not started, and the timing module 303 clears the operating duration.

Corresponding to the method for triggering the passive regeneration of the DPF provided by the embodiment of the present invention, referring to fig. 4, the embodiment of the present invention further provides a structural block diagram of a system for triggering the passive regeneration of the DPF, where the system includes: a processing unit 401, a calculation unit 402, a start unit 403, and a stop unit 404;

and the processing unit 401 is used for recording the operation time of the engine and periodically detecting the first temperature of the DPF when the engine is operated.

A calculating unit 402 for calculating an average temperature of the DPF during the operating time period using the first temperature when the operating time period is equal to the time threshold.

The starting unit 403 is configured to start a thermal management mode of the engine and raise the exhaust temperature of the engine to a second temperature if the average temperature is lower than the preset condition temperature.

In a specific implementation, the starting unit 403 is specifically configured to: activating a device in the preset device set of the engine, and raising the exhaust temperature of the engine to a second temperature.

And a stopping unit 404, configured to determine to trigger the DPF passive regeneration and stop the thermal management mode of the engine if an average value of the average temperature and the second temperature is greater than or equal to the condition temperature.

Preferably, the stopping unit 404 is further configured to: and resetting the running time length.

In the embodiment of the invention, when the engine operating period is equal to the time threshold, the average temperature in the operating period is calculated. And if the average temperature is lower than the condition temperature, starting the thermal management mode to raise the exhaust temperature of the engine to a second temperature until the average value of the average temperature and the second temperature is greater than or equal to the condition temperature, ensuring that the DPF passive regeneration is triggered, and stopping the thermal management mode. The problem that the DPF cannot be triggered to regenerate passively due to the use condition of the engine is avoided, so that frequent triggering of DPF active regeneration is avoided, the oil consumption of a vehicle is reduced, and the power of the vehicle is guaranteed.

Preferably, in conjunction with what is shown in fig. 4, the processing unit 401 includes: the detection module and the determination module, the execution principle of each module is as follows:

the determination module is used for determining that the inlet air temperature of the DPF is the first temperature of the DPF, or determining that the exhaust temperature of the DPF is the first temperature, or determining that the average value of the inlet air temperature and the exhaust temperature of the DPF is the first temperature.

Preferably, in conjunction with the content shown in fig. 4, the system further comprises:

and the zero clearing unit is used for determining to trigger the DPF to perform passive regeneration and clearing the running time length if the average temperature is greater than or equal to the condition temperature.

To sum up, the embodiment of the present invention provides a method and a system for triggering DPF passive regeneration, the method comprising: when the engine runs, recording the running time of the engine and periodically detecting the first temperature of the DPF; calculating the average temperature of the DPF during the running time period by using the first temperature when the running time period is equal to the time threshold value; if the average temperature is lower than the preset condition temperature, starting a heat management mode of the engine, and raising the exhaust temperature of the engine to a second temperature; and if the average value of the average temperature and the second temperature is greater than or equal to the condition temperature, determining to trigger the DPF to perform passive regeneration, and stopping the heat management mode of the engine. In the present aspect, when the engine operating duration is equal to the time threshold, the average temperature within the operating duration is calculated. And if the average temperature is lower than the condition temperature, starting a thermal management mode to raise the exhaust temperature of the engine to a second temperature until the average value of the average temperature and the second temperature is higher than or equal to the condition temperature, determining to trigger the DPF to passively regenerate, and stopping the thermal management mode. The problem that the DPF cannot be triggered to regenerate passively due to the use condition of the engine is avoided, so that frequent triggering of DPF active regeneration is avoided, the oil consumption of a vehicle is reduced, and the power of the vehicle is guaranteed.

The embodiments in the present specification are described in a progressive manner, and the same and similar parts among the embodiments are referred to each other, and each embodiment focuses on the differences from the other embodiments. In particular, the system or system embodiments are substantially similar to the method embodiments and therefore are described in a relatively simple manner, and reference may be made to some of the descriptions of the method embodiments for related points. The above-described system and system embodiments are only illustrative, wherein the units described as separate parts may or may not be physically separate, and the parts displayed as units may or may not be physical units, may be located in one place, or may be distributed on a plurality of network units. Some or all of the modules may be selected according to actual needs to achieve the purpose of the solution of the present embodiment. One of ordinary skill in the art can understand and implement it without inventive effort.

Those of skill would further appreciate that the various illustrative elements and algorithm steps described in connection with the embodiments disclosed herein may be implemented as electronic hardware, computer software, or combinations of both, and that the various illustrative components and steps have been described above generally in terms of their functionality in order to clearly illustrate this interchangeability of hardware and software. Whether such functionality is implemented as hardware or software depends upon the particular application and design constraints imposed on the implementation. Skilled artisans may implement the described functionality in varying ways for each particular application, but such implementation decisions should not be interpreted as causing a departure from the scope of the present invention.

The previous description of the disclosed embodiments is provided to enable any person skilled in the art to make or use the present invention. Various modifications to these embodiments will be readily apparent to those skilled in the art, and the generic principles defined herein may be applied to other embodiments without departing from the spirit or scope of the invention. Thus, the present invention is not intended to be limited to the embodiments shown herein but is to be accorded the widest scope consistent with the principles and novel features disclosed herein.

Claims

1. A method of triggering passive regeneration of a DPF, the method comprising:

when the engine runs, recording the running time of the engine;

periodically detecting an intake temperature and an exhaust temperature of a particulate trap (DPF) to determine a first temperature of the DPF;

if the average temperature is lower than the preset condition temperature, automatically starting a heat management mode of the engine, and raising the exhaust temperature of the engine to a second temperature;

2. The method of claim 1, wherein periodically detecting an intake temperature and an exhaust temperature of a particulate trap (DPF) to determine a first temperature of the DPF comprises:

3. The method of claim 1, wherein the automatically initiating the thermal management mode of the engine to raise the exhaust temperature of the engine to a second temperature comprises:

automatically turning on devices in a preset set of devices of the engine to raise an exhaust temperature of the engine to a second temperature.

4. The method of claim 1, further comprising, after said ceasing the thermal management mode for the engine:

and clearing the operation time length.

5. The method as set forth in claim 1, wherein said utilizing said first temperature after calculating an average temperature of said DPF over said time threshold further comprises:

6. A system for triggering passive regeneration of a DPF, the system comprising:

the processing unit is used for recording the running time of the engine when the engine runs; periodically detecting an intake temperature and an exhaust temperature of a particulate trap (DPF) to determine a first temperature of the DPF;

the starting unit is used for automatically starting a heat management mode of the engine and raising the exhaust temperature of the engine to a second temperature if the average temperature is lower than a preset condition temperature;

7. The system of claim 6, wherein the processing unit comprises:

8. The system according to claim 6, wherein the activation unit is specifically configured to: automatically turning on devices in a preset set of devices of the engine to raise an exhaust temperature of the engine to a second temperature.

9. The system of claim 6, wherein the stopping unit is further configured to: and clearing the operation time length.

10. The system of claim 6, further comprising: